摘要: |
通过田间试验,研究了小麦条锈病中心病株上夏孢子在风向不变的一段时间内,气流传播的二维空间分布。优用模型 E=exp(A—BDn)拟合叶面孢子着落量(Z)随距离(D)增加而递减。在试验条件下,以 n=1拟合最好。建立了 A 因初始菌量(S)和平均风速(W)、B 因平均风速而变的预测模型。根据田间病情分布形状推断,孢子的二维分布形状近似椭园形,并可假设抱子与风向垂直的横向分布为正态分布。孢子横向扩散程度受大气稳定度和初始菌量的影响,用椭园率(E)描述孢子的横向扩散程度,用初始菌量和平均风速建立了估计离心率的模型。采用正态分布密度函数与梯度模型 y=A-BDn[y=Ln(Z)]组建了孢子密度二维空间分布的模型。 |
关键词: 平均风速 分布模型 正态分布 分布形状 空间分布 预测模型 菌量 传播梯度 横向扩散 小麦条锈病 |
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SPATIAL DISTRIBUTION OF THE UREDOSPORES OF PUCCINIA STRIIFORMIS FROM THE FOCUS IN THE FIELD AFTER ONE-TIME DISSEMINATION BY WIND |
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Abstract: |
Two-dimensional distribution of the uredospores spreaded from a focus in the field after one-time dissemination by steady uni-driectional wind for a certain period was simulated based on the data obtained from specially designed field experiments.Assuming the final two-di- mensional distribution to be somewhat elliptical,Mackenzie's model (y=exp(A-B.D~n))was used to fit the linear distribution of spores along the main axis of the wind direction,and a cross-wind diffusion parameter E(ellipticity)was used to ... |
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